It's part of the developer notes in the documentation of Bitcoin Core:
Class names, function names, and method names are UpperCamelCase (PascalCase). Do not prefix class names with
C. See Internal interface naming style for an exception to this convention.
But I've seen many places in the codebase classes' name starting by
And many other examples. Is there a progress currently for changing these names? Or this rule is not apply to some classes?
Note that there's no description for this inconsistency in this part of the doc.